mariadb/sql/sp.h
unknown 0ea47f3ed4 BUG#9953: CONVERT_TZ requires mysql.time_zone_name to be locked
The problem was that some facilities (like CONVERT_TZ() function or
server HELP statement) may require implicit access to some tables in
'mysql' database.  This access was done by ordinary means of adding
such tables to the list of tables the query is going to open.
However, if we issued LOCK TABLES before that, we would get "table
was not locked" error trying to open such implicit tables.

The solution is to treat certain tables as MySQL system tables, like
we already do for mysql.proc.  Such tables may be opened for reading
at any moment regardless of any locks in effect.  The cost of this is
that system table may be locked for writing only together with other
system tables, it is disallowed to lock system tables for writing and
have any other lock on any other table.

After this patch the following tables are treated as MySQL system
tables:
  mysql.help_category
  mysql.help_keyword
  mysql.help_relation
  mysql.help_topic
  mysql.proc (it already was)
  mysql.time_zone
  mysql.time_zone_leap_second
  mysql.time_zone_name
  mysql.time_zone_transition
  mysql.time_zone_transition_type

These tables are now opened with open_system_tables_for_read() and
closed with close_system_tables(), or one table may be opened with
open_system_table_for_update() and closed with close_thread_tables()
(the latter is used for mysql.proc table, which is updated as part of
normal MySQL server operation).  These functions may be used when
some tables were opened and locked already.

NOTE: online update of time zone tables is not possible during
replication, because there's no time zone cache flush neither on LOCK
TABLES, nor on FLUSH TABLES, so the master may serve stale time zone
data from cache, while on slave updated data will be loaded from the
time zone tables.


mysql-test/r/help.result:
  Update result.
mysql-test/r/lock.result:
  Update result.
mysql-test/r/sp-error.result:
  Update result.
mysql-test/r/timezone2.result:
  Add result for bug#9953: CONVERT_TZ requires mysql.time_zone_name
  to be locked.
mysql-test/r/view.result:
  Update result: use table t3 rather than utilize MySQL system table.
mysql-test/t/help.test:
  Test that we can use HELP even under LOCK TABLES.
mysql-test/t/lock.test:
  Test LOCK TABLE on system tables.
mysql-test/t/timezone2.test:
  Add test case for bug#9953: CONVERT_TZ requires mysql.time_zone_name
  to be locked.
mysql-test/t/view.test:
  Update test: use table t3 rather that utilize MySQL system table.
sql/handler.h:
  Fix comment for 'count' parameter of check_if_locking_is_allowed().
  Add 'current' and 'system_count' parameters.
sql/item_create.cc:
  We no longer have LEX::add_time_zone_tables_to_query_tables().
sql/item_timefunc.cc:
  We no longer have LEX::time_zone_tables_used, so
  Item_func_convert_tz::fix_fields() became the same as base
  Item_date_func::fix_fields().
  
  my_tz_find() no longer takes table list, but takes THD pointer now.
sql/item_timefunc.h:
  Remove dead field and method.
sql/lock.cc:
  Pass values for 'current' and 'system_count' to
  check_if_locking_is_allowed().
sql/log_event.cc:
  We no longer have my_tz_find_with_opening_tz_tables(), its functions is
  performed by my_tz_find().
sql/mysql_priv.h:
  Add functions to work with MySQL system tables.
sql/set_var.cc:
  my_tz_find() no longer takes table list, but takes THD pointer now.
sql/sp.cc:
  Remove close_proc_table().  Use close_system_tables() instead.
  
  Use open_system_tables_for_read() and open_system_table_for_update().
sql/sp.h:
  Remove close_proc_table() declaration.
sql/sql_base.cc:
  Add implementation of open_system_tables_for_read(),
  close_system_tables(), open_system_table_for_update().
sql/sql_help.cc:
  Operate on MySQL system tables mysql.help_* with
  open_system_tables_for_read() and close_system_tables() to allow the
  usage of HELP statement under LOCK TABLES.
sql/sql_lex.cc:
  Remove LEX::time_zone_tables_used and
  LEX::add_time_zone_tables_to_query_tables() which are no longer used.
sql/sql_lex.h:
  Remove LEX::time_zone_tables_used and
  LEX::add_time_zone_tables_to_query_tables() which are no longer used.
sql/sql_parse.cc:
  Remove references to LEX::time_zone_tables_used and
  my_tz_check_n_skip_implicit_tables() which are no longer used.
sql/sql_show.cc:
  Use close_system_tables() instead of removed close_proc_table().
sql/sql_view.cc:
  LEX::time_zone_tables_used is no longer there.
sql/sql_yacc.yy:
  LEX::add_time_zone_tables_to_query_tables() is no longer there.
sql/table.cc:
  Add more tables that should be treated as MySQL system tables.
sql/share/errmsg.txt:
  Change the error message, as now we allow write-locking of several
  system tables if not mixed with ordinary tables.
sql/tztime.cc:
  Do not add time zone tables to the list of query tables in
  tz_init_table_list().
  
  Remove fake_time_zone_tables_list and my_tz_get_tables_list().
  
  In my_tz_init(), open mysql.time_zone_leap_second with
  simple_open_n_lock_tables(), but pass time zone name to my_tz_find(),
  which will open and close time zone tables as necessary.
  
  In tz_load_from_open_tables() do not call table->use_all_columns(), as
  this was already done in open_system_tables_for_read().
  
  my_tz_find() takes THD pointer instead of table list, and calls
  open_system_tables_for_read() and close_system_tables() as necessary.
  
  Remove my_tz_find_with_opening_tz_tables().
sql/tztime.h:
  Remove declarations of my_tz_get_table_list(),
  my_tz_find_with_opening_tz_tables(), fake_time_zone_tables_list,
  definition of my_tz_check_n_skip_implicit_tables().
  Update prototype for my_tz_find().
storage/csv/ha_tina.cc:
  Add new parameters to check_if_locking_is_allowed().
storage/csv/ha_tina.h:
  Add new parameters to check_if_locking_is_allowed().
storage/myisam/ha_myisam.cc:
  Add new parameters to check_if_locking_is_allowed().  In this
  function we count system tables.  If there are system tables, but
  there are also non-system tables, we report an error.
storage/myisam/ha_myisam.h:
  Add new parameters to check_if_locking_is_allowed().
2007-03-09 13:12:31 +03:00

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C++

/* -*- C++ -*- */
/* Copyright (C) 2002 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef _SP_H_
#define _SP_H_
// Return codes from sp_create_*, sp_drop_*, and sp_show_*:
#define SP_OK 0
#define SP_KEY_NOT_FOUND -1
#define SP_OPEN_TABLE_FAILED -2
#define SP_WRITE_ROW_FAILED -3
#define SP_DELETE_ROW_FAILED -4
#define SP_GET_FIELD_FAILED -5
#define SP_PARSE_ERROR -6
#define SP_INTERNAL_ERROR -7
#define SP_NO_DB_ERROR -8
#define SP_BAD_IDENTIFIER -9
#define SP_BODY_TOO_LONG -10
/* Drop all routines in database 'db' */
int
sp_drop_db_routines(THD *thd, char *db);
sp_head *
sp_find_routine(THD *thd, int type, sp_name *name,
sp_cache **cp, bool cache_only);
int
sp_exist_routines(THD *thd, TABLE_LIST *procs, bool any, bool no_error);
int
sp_routine_exists_in_table(THD *thd, int type, sp_name *name);
int
sp_create_procedure(THD *thd, sp_head *sp);
int
sp_drop_procedure(THD *thd, sp_name *name);
int
sp_update_procedure(THD *thd, sp_name *name, st_sp_chistics *chistics);
int
sp_show_create_procedure(THD *thd, sp_name *name);
int
sp_show_status_procedure(THD *thd, const char *wild);
int
sp_create_function(THD *thd, sp_head *sp);
int
sp_drop_function(THD *thd, sp_name *name);
int
sp_update_function(THD *thd, sp_name *name, st_sp_chistics *chistics);
int
sp_show_create_function(THD *thd, sp_name *name);
int
sp_show_status_function(THD *thd, const char *wild);
/*
Procedures for pre-caching of stored routines and building table list
for prelocking.
*/
void sp_get_prelocking_info(THD *thd, bool *need_prelocking,
bool *first_no_prelocking);
void sp_add_used_routine(LEX *lex, Query_arena *arena,
sp_name *rt, char rt_type);
void sp_remove_not_own_routines(LEX *lex);
void sp_update_sp_used_routines(HASH *dst, HASH *src);
int sp_cache_routines_and_add_tables(THD *thd, LEX *lex,
bool first_no_prelock);
int sp_cache_routines_and_add_tables_for_view(THD *thd, LEX *lex,
TABLE_LIST *view);
int sp_cache_routines_and_add_tables_for_triggers(THD *thd, LEX *lex,
TABLE_LIST *table);
extern "C" byte* sp_sroutine_key(const byte *ptr, uint *plen, my_bool first);
/*
Routines which allow open/lock and close mysql.proc table even when
we already have some tables open and locked.
*/
TABLE *open_proc_table_for_read(THD *thd, Open_tables_state *backup);
/*
Do a "use new_db". The current db is stored at old_db. If new_db is the
same as the current one, nothing is changed. dbchangedp is set to true if
the db was actually changed.
*/
int
sp_use_new_db(THD *thd, LEX_STRING new_db, LEX_STRING *old_db,
bool no_access_check, bool *dbchangedp);
#endif /* _SP_H_ */